Hotel Features. Danubius Health Spa Resort Butterfly has an indoor pool, a sauna, and a fitness center. This spa hotel offers a restaurant, a coffee shop/café, and a poolside bar. Guests are served a complimentary breakfast each morning. Additional amenities include spa services, a terrace, and multilingual staff. For a surcharge, guests have access to a roundtrip airport shuttle(available on request). This is a smoke-free property.